Most people who follow robotics and exoskeletonry are aware of the superannuated surge projected for the Japanese population in coming decades, and the governmental plan to mostly have robots look after the burgeoning blue-rinsed hordes.
This will free up the relatively few folks of working age left in the land of the Rising …

Ripley's Grandma...

Doesn't "forbid"

As I understand it, Japan doesn't "forbid" immigration. It does, however, make it very difficult to do so. You basically have to show that you're more Japanese than the most tradition-bound Japanese known by the inspectors. Bribes also help. Allegedly.